Keplinger went to the hospital for his injuries. He had a laceration to his face, near an ear, according to earlier reports.

He testified he was off work for three months.

Before the alleged assault, Keplinger had gone to Johnson’s cell while Johnson was in the prison yard or elsewhere to take down a blanket the prisoner had hung in a window, which is not allowed.

The officer then found the “spud juice,” prohibited alcohol typically made from fruit.

Keplinger opened the container to see how long the substance had fermented and it sprayed all over the place, he testified, responding to questions posed by Susan Dehncke, Johnson’s lawyer.

Because of the mess, Johnson asked for cleaning materials, according to testimony. He was laughing about it, Keplinger said.

Keplinger said he always seemed to get along “pretty good” with Johnson. When Dehncke asked if he had ever called Johnson a derogatory name, he responded: “Absolutely not.”

Johnson was sentenced in 2011 to 11 years, three months to 30 years in prison for carjacking, multiple counts of armed robbery and first-degree home invasion in Saginaw County, Michigan Department of Corrections records show.

At the time of the alleged assault, Johnson was housed in a Level IV unit. He now is in a Level V unit, the highest security level, at Ionia Correctional Facility, east of Grand Rapids.